This invention relates to an electronic part such as a capacitor, a resistor and the like.
In recent years, in order to make sure of the safety of electric appliances using electronic parts, it is becoming a serious problem to make the electronic parts nonflammable. Current electronic parts are coated with a nonflammable organic or inorganic coating for practical use. However, these are not the truly satisfactory ones from the viewpoint of nonflammability.
For example, a ceramic capacitor is widely used in the electric appliances because of its excellent electrical characteristics and handling ability. A typical ceramic capacitor is covered with a flame deterrent coating such as an epoxy rein family coating and a silicone resin family coating. However, in cases where an extremely high voltage is applied to the electric appliances due to lightning or the like, the ceramic capacitor used in the electric appliances undergoes a dielectric breakdown so that a remarkably large overcurrent flows through the ceramic capacitor to heat it, resulting in an apprehension that the currently used flame deterrent coating material might not stand the heat generated to catch fire if worst comes to worst.
To avoid such problem of safety, Japanese Patent Unexamined Publication No. 4-369821 discloses an arrangement in which a lead portion is made of a material for fuse so that it melts to cut off the current when an overcurrent flows through it. Japanese Utility Model Registration No. 2048581 discloses an arrangement in which a capacitor is covered with a cap that is not completely stripped off at the time when the capacitor is exploded.
However, according to these arrangements, occurrence of fire is not perfectly suppressed, and therefore it is impossible to completely eliminate the possibility that the electric appliances may catch fire.